CN208966235U - A kind of pressure maintaining cylinder sealing structure - Google Patents

Abstract

The utility model relates to a kind of pressure maintaining cylinder sealing structures, including core barrel, interior bar, drilling machine outer cylinder and flap valve, the lower end of interior bar and the inner wall of core barrel seal and cooperate, gas cavity, fluid passage and pressure release passage are equipped in interior bar, piston is equipped in gas cavity, fluid passage upper end is connected to gas cavity, and for the lower ending opening of fluid passage in the bottom surface of interior bar, safety valve is installed in pressure release passage inlet；Flap valve includes valve seat and sealing flap, and valve seat is mounted on drilling machine outer tube inner wall, and sealing flap one end is flexibly connected with valve seat upper end lateral wall, when core barrel is located in valve seat, it seals flap and opens 90 °, when core barrel is up-shifted to certain altitude, sealing flap is closed.The utility model realizes lower end sealing using flap valve, and sealing flap is hidden between inner/outer tube when unlatching, saves space, can eliminate the limitation to core-drilling diameter；Pressure release passage and safety valve are set in upper end sealing part position, the timely pressure release of energy reduces rapidly the pressure in cylinder.

Description

A kind of pressure maintaining cylinder sealing structure

Technical field

The utility model relates to coring equipment technical field more particularly to a kind of pressure maintaining cylinder sealing structures.

Background technique

Core drilling be Solid Mineral geological prospecting frequently with exploration means.Tubular drill bit and drilling tool bottom hole circumferentially Cyclic annular fractured rock retains a columnar rock core in bottom hole central part, and removal of core is to study geology and mine out of hole The case where production, therefore referred to as core drilling.

Deep ground deep-sea area strata pressure is high, when carrying out core drilling, after guaranteeing that the rock sample got reaches ground Still in hyperbaric environment, it need to store using pressure maintaining coring tube and transport sample.Pressure maintaining coring tube hangs in Shen Di coring area vertically, when After rock sample enters pressure maintaining cylinder by lifting, pressure maintaining cylinder upper end generally uses piston to seal, and pressure maintaining cylinder lower end generallys use ball valve Sealing, to guarantee hyperbaric environment in cylinder.But ball-valve structure is more complicated, and volume exclusion is big, limits the diameter of core-drilling, ball Valve processing technology require it is high, and when pressure is larger, liquid inside pressure maintaining cylinder can the gap between ball valve and core barrel seep Out, higher pressure cannot be maintained.

In addition, deep ground blue water is usually with the presence of a large amount of fluids, therefore the often presence in the form of hydraulic pressure of institute's packing pressure.It is existing The sealing of some pressure maintaining cylinders upper end uses movement, and when drilling machine starts operation, the cleaner for high-pressure drilling fluid being passed through can be under core barrel End enters inside core barrel, increases core barrel internal pressure, and piston sealing structure pressure regulation ability is limited, if in core barrel Pressure is excessive, is easily damaged equipment.

Utility model content

The utility model is intended to provide a kind of pressure maintaining cylinder sealing structure, realizes the sealing of pressure maintaining cylinder lower end using flap valve, turns over Plate valve structure is simple, and is able to maintain that higher pressure, and sealing performance can be improved；In addition, also having additional pressure release passage and peace Full valve, when cylinder pressure reaches predetermined value, safety valve is opened, can timely pressure release, and pressure relief capability is strong, can effectively ensure that rock Heart probing safety carries out.

In order to achieve the above objectives, the technical solution adopted in the utility model is as follows:

A kind of pressure maintaining cylinder sealing structure, including core barrel, interior bar, drilling machine outer cylinder and flap valve, the lower end of the interior bar are stretched Into in core barrel, the lower end of interior bar and the inner wall of core barrel seal and cooperate, and gas cavity and fluid passage, gas are equipped in interior bar Piston two is equipped in cavity, fluid passage upper end is connected to gas cavity, and the lower ending opening of fluid passage is in the bottom surface of interior bar；

Flap valve includes valve seat and sealing flap, and valve seat is coaxially mounted on drilling machine outer tube inner wall, sealing flap one end with Valve seat upper end lateral wall is flexibly connected, and is had at the top of valve seat and the sealing matched sealing valve port face of flap；When core barrel is located at valve seat When middle, sealing flap opens 90 ° and between core barrel and drilling machine outer cylinder；When core barrel is up-shifted to certain altitude When, it is in sealing contact with sealing valve port face that sealing flap returns to valve seat top surface.

Further, interior bar bottom is expanded, and the outer wall of interior bar bulb is equipped with sealing ring one, in sealing ring one and core barrel Wall sealing cooperation, forms liquid reservoir one, core barrel upper side between the outer wall and core barrel inner wall of one top interior bar of sealing ring Wall is equipped with overflow hole；

Pressure release passage is equipped in interior bar, the outlet of pressure release passage is connected to liquid reservoir one, and the entrance of pressure release passage is located at The inlet of interior bar bottom surface, pressure release passage is equipped with safety valve.

Wherein, interior bar outer wall is equipped with sealing ring two, and sealing ring two is located between the outlet and sealing ring one of pressure release passage； When interior bar is moved to top dead centre relative to core barrel, sealing ring two and the sealing of core barrel inner wall cooperate, and overflow hole is located at sealing Between circle two and sealing ring one.

Further, interior bar lower end is set with end cap cap, and the region between end cap cap inner wall and interior bar bottom surface constitutes liquid Cavity two, end cap cap lower end are equipped with piston one, and piston one is equipped with liquid flow through-hole, and end cap cap corresponds to the position of liquid flow through-hole Through-hole is installed.

Preferably, strainer is housed in liquid reservoir two.

Further, a kind of pressure maintaining cylinder sealing structure further includes trigger mechanism, and trigger mechanism includes triggering inner cylinder and triggering Block, triggering inner cylinder side wall are equipped with through-hole, triggering block is placed in through-hole, and core barrel bottom outside wall has to be adapted to triggering block Lug boss；Drilling machine outer tube inner wall has the escape port being adapted to lug boss, and triggering block is located above sealing flap, and escape port is located at touching It sends out above block；

When core barrel is located in valve seat, trigger inner cylinder positioned at core barrel and drilling machine outer cylinder between, trigger inner cylinder lower end and The cooperation of valve seat seam allowance, triggering block externally protrude out in the inner sidewall of triggering inner cylinder, and sealing flap is located between triggering inner cylinder and drilling machine outer cylinder； When core barrel is up-shifted to certain altitude, it is in sealing contact with sealing valve port face that sealing flap returns to valve seat top surface, triggers Inner cylinder bottom is pressed on sealing flap.

Further, trigger mechanism further includes triggering spring, and triggering spring pocket is outside triggering inner cylinder, outside the triggering inner cylinder Wall is equipped with shoulder, and triggering lower spring end is pressed on shoulder, and triggering spring upper end is withstood on the step surface of drilling machine outer cylinder, triggers spring Above triggering block.

Preferably, when sealing 90 ° of flap unlatching, sealing flap inner surface is bonded and outside it completely with triggering inner tank theca Surface and valve seat lateral wall are in the same cylindrical surface.

Further, sealing flap one end is hinged by spring leaf and valve seat upper end lateral wall.

Wherein, sealing ring is equipped between the outer wall of valve seat and the inner wall of drilling machine outer cylinder.

Compared with prior art, the utility model has the following beneficial effects:

1. the utility model realizes lower end sealing using flap valve, flap valve is simple, and sealing flap is hidden when unlatching Between inner/outer tube, space is saved, the limitation to core-drilling diameter can be eliminated；

2. sealing flap is pressurized in the triggering inner cylinder of falling, and seal pressure is big, can further improve when flap valve is closed The sealing performance of valve；

3., if fluid pressure is excessive in core barrel, when reaching predetermined value, safety valve will be opened in location of the coring procedure, Rock core liquid within the cartridge will enter in the liquid reservoir one between interior bar and core barrel along the liquid flow through-hole on piston one, and It is overflowed with the overfolw hole on core barrel top, carries out pressure release in time, reduce rapidly the pressure in core barrel, avoid pressure excessive and damage Evil equipment；

4. the utility model can carry out pressure compensation to core barrel, maintain core barrel automatically by gas cavity and piston Interior pressure is stablized, and realizes pressure maintaining coring.

Detailed description of the invention

The schematic diagram of the utility model before Fig. 1 is coring；

Fig. 2 is the enlarged drawing in Fig. 1 at A；

Fig. 3 is the enlarged drawing in Fig. 1 at B；

Fig. 4 is the enlarged drawing in Fig. 1 at C；

The structural schematic diagram of the utility model when Fig. 5 is coring；

Fig. 6 is the enlarged drawing in Fig. 5 at A；

Fig. 7 is the enlarged drawing in Fig. 5 at B；

Fig. 8 is the enlarged drawing in Fig. 5 at C；

Fig. 9 is the schematic diagram of the utility model after the completion of coring；

Figure 10 is the enlarged drawing in Fig. 9 at A；

Figure 11 is the enlarged drawing in Fig. 9 at B；

Figure 12 is the structural schematic diagram of flap valve；

In figure: 1- core barrel, 2- interior bar, 3- safety valve, 4- piston one, 5- liquid reservoir one, 6- pressure release passage, 7- liquid Body cavity two, 8- strainer, 9- end cap cap, 10- gas cavity, 11- piston two, 12- sealing ring one, 13- overflow hole, 14- liquid Channel, 15- liquid flow through-hole, 16- drilling machine outer cylinder, 17- drill bit, 18- flap valve, 19-O type circle, 20- sealing ring two, 21- limit Position step one, 22- limited step two, 23- catch core device, 24- spring leaf, 25- escape port, 26- lug boss, the upper outer cylinder of 161-, Outer cylinder, 163- threaded connecting sleeve, 31- valve seat, 32- seal flap, 41- shaft, 42- elastic slice, 311- sealing valve port under 162- Face, 321- groove, 322- sealing ring three, 51- triggering spring, 52- trigger inner cylinder, 53- triggering block, 521- shoulder.

Specific embodiment

In order to make the purpose of the utility model, technical solutions and advantages more clearly understood, below in conjunction with attached drawing, to this reality It is further elaborated with novel.

As shown in figs. 1-11, a kind of pressure maintaining cylinder sealing structure disclosed by the utility model, including core barrel 1, interior bar 2, brill Machine outer cylinder 16 and flap valve 18, as shown in Fig. 1,4, the lower end of interior bar 2 is put in core barrel 1, and 2 bottom of interior bar is expanded, interior bar 2 The outer wall of bulb is equipped with sealing ring 1, and sealing ring 1 and the sealing of 1 inner wall of core barrel cooperate.In 2 lower outside wall of interior bar Equipped with limited step 1,1 upper inner wall of core barrel has the limited step 2 22 being adapted to limited step 1, limiting stand Rank 2 22 is located at 13 top of overflow hole.

It is equipped with gas cavity 10 and fluid passage 14 in interior bar 2, is equipped with piston 2 11, fluid passage 14 in gas cavity 10 Upper end is connected to gas cavity 10, and the lower ending opening of fluid passage 14 is in the bottom surface of interior bar 2.Piston 2 11 is used to completely cut off gas-liquid, Realize the sealing of core barrel upper end.Pass through the movement of piston 2 11, the pressure in adjustable core barrel 1 simultaneously.Gas cavity 10 can be connected with gas charge and discharge device, convenient for 10 inflation/deflation of gas cavity.

2 lower end of interior bar is set with end cap cap 9, and the region between 2 bottom surface of 9 inner wall of end cap cap and interior bar constitutes liquid reservoir two 7, gas cavity 10 is connected to by fluid passage 14 with liquid reservoir 27.Strainer 8 is housed in liquid reservoir 27, can be filtered Fall impurity, impurity is avoided to enter in gas cavity 10.9 lower end of end cap cap is equipped with the piston 1 being adapted to 1 inner wall of core barrel, Piston 1 is mounted on end cap cap 9 by bolt, and piston 1 is equipped with liquid flow through-hole 15, the corresponding liquid communication of end cap cap 9 The position in hole 15 is equipped with through-hole.15 eccentric setting of liquid flow through-hole is equipped with O-ring 19 on piston 1.In another implementation Two are had in mode on piston 1, two pistons 1 are affixed, 15 face of liquid flow through-hole on two pistons 1, position In being equipped with O-ring 19 on the piston 1 of lower section.

In another embodiment, liquid is formed between 1 inner wall of outer wall and core barrel of one 12 top interior bar 2 of sealing ring Body cavity 1,1 upper portion side wall of core barrel are equipped with overflow hole 13.Be equipped with pressure release passage 6 in interior bar 2, the outlet of pressure release passage 6 with Liquid reservoir 1 is connected to, and the entrance of pressure release passage 6 is located at 2 bottom surface of interior bar, and the inlet of pressure release passage 6 is equipped with safety valve 3, Pressure release passage 6 is separated with liquid reservoir 27 by safety valve 3, and safety valve 3 can be opened when pressure reaches certain value, for timely Pressure release.2 outer wall of interior bar is equipped with sealing ring 2 20, and sealing ring 2 20 is located between the outlet and sealing ring 1 of pressure release passage 6.

As shown in Figure 1,3, flap valve 18 includes valve seat 31 and sealing flap 32, and valve seat 31 is coaxially mounted to drilling machine outer cylinder On 16 inner walls, sealing 32 one end of flap is flexibly connected with 31 upper end lateral wall of valve seat, is had at the top of valve seat 31 and sealing flap 32 The sealing valve port face 311 matched.

Wherein, drilling machine outer cylinder 16 includes upper outer cylinder 161, lower outer cylinder 162 and threaded connecting sleeve 163, threaded connecting sleeve 163 Lower end is equipped with internal screw thread, and 163 upper end of threaded connecting sleeve is equipped with external screw thread, under the upper end of lower outer cylinder 162 and threaded connecting sleeve 163 End is threadedly coupled, and the lower end of upper outer cylinder 161 is connect with the threaded upper ends of threaded connecting sleeve 163.Wherein, the bottom surface of valve seat 31 with The top surface of threaded connecting sleeve 163 contacts, and sealing ring, sealing ring installation are equipped between the outer wall of valve seat 31 and the inner wall of upper outer cylinder 161 On 31 outer wall of valve seat.

In another embodiment, a kind of pressure maintaining cylinder sealing structure further includes trigger mechanism, and trigger mechanism includes triggering Spring 51, triggering inner cylinder 52 and triggering block 53, triggering 52 side wall of inner cylinder are equipped with through-hole, and triggering block 53 is placed in through-hole, rock 1 bottom outside wall of heart cylinder has the lug boss 26 being adapted to triggering block 53.16 inner wall of drilling machine outer cylinder has to be kept away with what lug boss 26 was adapted to Allow mouth 25, triggering block 53 is located at 32 top of sealing flap, and escape port 25 is located above triggering block 53.51 sets of spring of triggering is being touched It sends out outside inner cylinder 52, triggering 52 outer wall of inner cylinder is equipped with shoulder 521, and triggering 51 lower end of spring is pressed on shoulder 521, triggered on spring 51 End is withstood on the step surface of drilling machine outer cylinder 16, and triggering spring 51 is located at 53 top of triggering block.

As shown in Figs 1-4, before core work starts, 1 lower end of core barrel passes through valve seat 31 and extends to drilling machine outer cylinder 16 Drill bit 17 is installed in bottom, 16 lower end of drilling machine outer cylinder, and the lower end of interior bar 2 extends in drill bit 17, and core barrel 1 is located at valve seat at this time When in 31, inner cylinder 52 is triggered between core barrel 1 and drilling machine outer cylinder 16, and triggering inner cylinder 52 and sealing flap 32 are in close contact Sealing flap 32 can be limited to rotate.It triggers 52 lower end of inner cylinder and 31 seam allowance of valve seat cooperates, triggering block 53 externally protrudes out in triggering inner cylinder 52 Inner sidewall, the outside of triggering block 53 contacts with 16 inner wall of drilling machine outer cylinder, and the inside of triggering block 53 is contacted with 1 outer wall of core barrel, Flap 32 is sealed to open 90 ° and be located between triggering inner cylinder 52 and drilling machine outer cylinder 16.

As viewed in figures 5-8, being passed through with drilling fluid, drilling machine 17 fall, and core barrel 1 is downward with drilling machine outer cylinder 16 at this time Mobile, drilling fluid is gradually filled into core barrel 1, during this, if the pressure in core barrel 1 is greater than 10 upper chambers of gas cavity Intracorporal pressure, partially liq enters liquid reservoir 27 through liquid flow through-hole 15, followed by strainer 8 and fluid passage 14 It enters in gas cavity 10, compression piston 2 11 is until gas-liquid reaches balance.If pressure reaches predetermined value, if safety valve 3 It is opened, liquid enters in liquid reservoir 1 through pressure release passage 6, and rock core is discharged eventually by the overflow hole 13 on 1 top of core barrel Cylinder 1, avoidable 1 pressure of core barrel is excessive, the training equipments such as protection drilling machine.

Meanwhile with the drilling of drill bit 17, core enters in core barrel 1 from 1 lower end of core barrel and is grabbed by catching core device 23 Tightly, water environment in situ can invade in core barrel 1 at this time.As shown in Figure 5,6, when limited step 1 and limited step 2 22 When offseting, core barrel 1 and interior bar 2 cannot axially opposing movement again, interior bar 2 is moved to top dead centre relative to core barrel 1, close at this time Seal 2 20 and the sealing of 1 inner wall of core barrel cooperate, and overflow hole 13 is between sealing ring 2 20 and sealing ring 1.At this point, rock Heart cylinder 1 is still located in valve seat 31.

After drill bit 17 stops brill, when lifting interior bar 2 upwards, the uplink together of core barrel 1 can be driven, core device 7 is caught and grabs rock core simultaneously Moved up with core barrel 1, as shown in figs. 9-11, after core barrel 1 crosses flap valve 18 by lifting, 1 bottom of core barrel it is convex Playing portion 26 drives triggering block 53 to rise, and then drives the triggering compression of inner cylinder 52 triggering spring 51 and rises, when triggering 52 bottom of inner cylinder After sealing flap 32 is crossed in portion, triggering 52 pairs of sealing flaps 32 of inner cylinder lose restriction effect, and sealing flap 32 inverts, and return to valve seat 31 top surfaces and sealing valve port face 311 are in sealing contact, to close flap valve 18, realize the sealing of 1 lower end of core barrel, pass through upper end The collective effect of piston 2 11 and lower end flap valve 18 can effectively avoid the loss of liquid in core barrel 1.

When triggering block 53 with core barrel 1 reach drilling machine outer cylinder 16 escape port 25 when, triggering block 53 can radial displacement after And it is detached from the effect of 1 lug boss 26 of core barrel；After escape port 25 are crossed in 1 bottom of core barrel, triggering block 53 loses core barrel 1 Active force, triggering inner cylinder 52 trigger spring 51 elastic force and self gravity under the action of drive triggering block 53 glide, most Final pressure applies seal pressure on sealing flap 32, to flap valve 18.

The structure of flap valve 18 is as shown in figure 12 in present embodiment, and sealing 32 one end of flap passes through spring leaf 24 and valve seat 31 upper end lateral walls are hinged.Wherein, spring leaf 24 includes shaft 41 and elastic slice 42, and 31 side wall top of valve seat has suitable with 41 phase of shaft There are the groove 321 for accommodating elastic slice 42 in the shaft accommodation groove matched, sealing 32 outer surface of flap.Elastic slice 42 is shaped form steel disc, curve Fashioned iron piece is stuck at groove 321, and shaped form steel disc can stretch under external force, curved surface can become plane and with sealing The groove 321 of 32 outer surface of flap is bonded completely.When sealing flap 32 is crossed in triggering 52 bottom of inner cylinder, it is clipped in drilling machine outer cylinder 16 Elastic slice 42 between sealing flap 32 discharges elastic force, and sealing flap 32 inverts under 42 elastic force of elastic slice and self gravitation effect, Sealing cooperation is realized with valve seat 31.

When sealing 90 ° of the unlatching of flap 32, sealing 32 inner surface of flap is bonded and outside it completely with triggering 52 outer wall of inner cylinder Surface and 31 lateral wall of valve seat are in the same cylindrical surface.Sealing flap 32 is to intercept semicircle section of jurisdiction by circular conical surface or Surface of Sphere to obtain The space curved surface obtained, semicircle section of jurisdiction outer diameter are consistent with 31 outer diameter of valve seat.Sealing 32 periphery of flap is provided with for installing sealing ring 3 322 annular groove is equipped with sealing ring 3 322 in annular groove.

In another embodiment, sealing flap 32 is cut with scissors by pin shaft and torque spring and 31 upper end lateral wall of valve seat It connects.

In drilling process, pressure reduction in core barrel 1,2 11 following pressure of piston is reduced, and balance is broken, gas cavity Gas expansion in 10, piston 2 11 move down, and compress liquid in core barrel 1, reach balance again.

The utility model realizes lower end sealing using flap valve, and structure is simple, saves space, can eliminate straight to core-drilling The limitation of diameter；Upper end sealing structure has explosion prevention function, good reliability.

Certainly, the utility model can also have other numerous embodiments, without departing substantially from the spirit of the present invention and its essence In the case where, those skilled in the art can make various corresponding changes and modifications, but these according to the utility model Corresponding changes and modifications all should belong to the protection scope of the utility model the attached claims.

Claims (10)

1. a kind of pressure maintaining cylinder sealing structure, it is characterised in that: including core barrel (1), interior bar (2), drilling machine outer cylinder (16) and turnover panel Valve (18), the lower end of the interior bar (2) are put in core barrel (1), and the lower end of interior bar (2) is matched with the inner wall sealing of core barrel (1) It closes, gas cavity (10) and fluid passage (14) is equipped in interior bar (2), is equipped with piston two (11), liquid in gas cavity (10) Channel (14) upper end is connected to gas cavity (10), and the lower ending opening of fluid passage (14) is in the bottom surface of interior bar (2)；

Flap valve (18) includes valve seat (31) and sealing flap (32), and valve seat (31) is coaxially mounted to drilling machine outer cylinder (16) inner wall On, sealing flap (32) one end is flexibly connected with valve seat (31) upper end lateral wall, is had at the top of valve seat (31) and sealing flap (32) Matched sealing valve port face (311)；When core barrel (1) is located in valve seat (31), sealing flap (32) opens 90 ° and is located at rock Between heart cylinder (1) and drilling machine outer cylinder (16)；When core barrel (1) is up-shifted to certain altitude, sealing flap (32) is returned to Valve seat (31) top surface and sealing valve port face (311) are in sealing contact.

2. a kind of pressure maintaining cylinder sealing structure according to claim 1, it is characterised in that: interior bar (2) bottom is expanded, interior bar (2) outer wall of bulb is equipped with sealing ring one (12), and sealing ring one (12) and the sealing of core barrel (1) inner wall cooperate, sealing ring one (12) liquid reservoir one (5) are formed between the outer wall and core barrel (1) inner wall of top interior bar (2), core barrel (1) upper portion side wall is set There are overflow hole (13)；

Pressure release passage (6) are equipped in interior bar (2), the outlet of pressure release passage (6) is connected to liquid reservoir one (5), pressure release passage (6) Entrance be located at interior bar (2) bottom surface, the inlet of pressure release passage (6) is equipped with safety valve (3).

3. a kind of pressure maintaining cylinder sealing structure according to claim 2, it is characterised in that: interior bar (2) outer wall is equipped with sealing Two (20) are enclosed, sealing ring two (20) is located between the outlet and sealing ring one (12) of pressure release passage (6)；When interior bar (2) relative to When core barrel (1) is moved to top dead centre, sealing ring two (20) and the sealing of core barrel (1) inner wall cooperate, and overflow hole (13) is located at close Between seal two (20) and sealing ring one (12).

4. a kind of pressure maintaining cylinder sealing structure according to claim 1,2 or 3, it is characterised in that: interior bar (2) lower end is set with End cap cap (9), the region between end cap cap (9) inner wall and interior bar (2) bottom surface constitute liquid reservoir two (7), end cap cap (9) lower end Piston one (4) is installed, piston one (4) is equipped with liquid flow through-hole (15), the position of end cap cap (9) corresponding liquid flow through-hole (15) Through-hole is installed.

5. a kind of pressure maintaining cylinder sealing structure according to claim 4, it is characterised in that: equipped with filter in liquid reservoir two (7) Net (8).

6. a kind of pressure maintaining cylinder sealing structure according to claim 1, it is characterised in that: further include trigger mechanism, trigger machine Structure includes triggering inner cylinder (52) and triggering block (53), and triggering inner cylinder (52) side wall is equipped with through-hole, and triggering block (53) is placed in logical Kong Zhong, core barrel (1) bottom outside wall have the lug boss (26) being adapted to triggering block (53)；Drilling machine outer cylinder (16) inner wall have with it is convex The escape port (25) of portion (26) adaptation is played, triggering block (53) is located above sealing flap (32), and escape port (25) is located at triggering block (53) top；

When core barrel (1) is located in valve seat (31), triggering inner cylinder (52) is located between core barrel (1) and drilling machine outer cylinder (16), It triggers inner cylinder (52) lower end and valve seat (31) seam allowance cooperates, triggering block (53) externally protrudes out in the inner sidewall of triggering inner cylinder (52), sealing Flap (32) is located between triggering inner cylinder (52) and drilling machine outer cylinder (16)；When core barrel (1) is up-shifted to certain altitude, Sealing flap (32) returns to valve seat (31) top surface and sealing valve port face (311) is in sealing contact, and triggering inner cylinder (52) bottom is pressed in close It seals on flap (32).

7. a kind of pressure maintaining cylinder sealing structure according to claim 6, it is characterised in that: trigger mechanism further includes triggering spring (51), triggering spring (51), which covers, is triggering inner cylinder (52) outside, and triggering inner cylinder (52) outer wall is equipped with shoulder (521), triggers bullet Spring (51) lower end is pressed on shoulder (521), and triggering spring (51) upper end is withstood on the step surface of drilling machine outer cylinder (16), triggers spring (51) it is located above triggering block (53).

8. a kind of pressure maintaining cylinder sealing structure according to claim 6 or 7, it is characterised in that: when sealing flap (32) is opened At 90 °, sealing flap (32) inner surface is bonded completely with triggering inner cylinder (52) outer wall and its outer surface and valve seat (31) lateral wall In the same cylindrical surface.

9. a kind of pressure maintaining cylinder sealing structure according to claim 1, it is characterised in that: sealing flap (32) one end passes through bullet Reed (24) and valve seat (31) upper end lateral wall are hinged.

10. a kind of pressure maintaining cylinder sealing structure according to claim 1, it is characterised in that: the outer wall and drilling machine of valve seat (31) Sealing ring is equipped between the inner wall of outer cylinder (16).